Boiler-furnace



(No Model.)

B.- STEWART.

BOILER FURNACE. N0.-364,382. Patented June 7, 1887.

@543 aim wag N PETERS. Pholol lhognphur, Wavhingtan'. D. C.

sists in certain features of construction and UNTTED STATES PATENT @EEICE.

ROBERT STEW'ART, OF LOUISVILLE, KENTUCKY.

BOILER-FURNACE.

SPECIFICATION forming part of Letters Patent No. 364,382, dated June 7, 1887.

A pplicalion filed April 15, 1887. Serial No. 234,945. (No model.) I

To aZZ whom it may concern.-

Be it known that I, ROBERT STEWART, of Louisville, in the county of Jefferson and State of Kentucky, have invented certain new and usefullmprovements in Methods of Constructing Boiler-Furnaees; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improved method of constructing aboiler-furnaee, and more particularly to an improvement in furnaces for return-flue boilers.

Heretofore boilers with tubular tlues extending longitudinally from one head to the other to return the heated products of fuel combustion from the rear end of the boiler to the front end, and thence up the chimney or stack, have been provided with masonry walls of brick or stone, that inclosed a flue or passage extend ing from the bridge-wall or back wall of the fire-chamber to the rear of the boiler. Generally,this flue has been made of considerable depth and intersected a chamber at the rear of the boiler, said flue being of greater dimensions than the combined area of the flucs in the boiler.

The object of my present invention is to constructthe furnace-walls of the boiler and so proportion them that the hot products of fuel combustion will be made to more closely on velop the lower portion of the boiler at its rear end and rear sheet of the same, so as to more completely utilize the heat developed by fuel combustion and effect economy in consumption of the same.

WVith this object in view my invention concombinations of parts,that will be hereinafter described, and pointed out in the claims.

Referring to the drawings, making apart of this speeification,Figure 1 is a side elevation in section through the longitudinal center of the boiler, showing the interior construction of the furnace-walls. Fig. 2 is a rear end elevation of the boiler and its furnace-walls, showing the relative position of parts of this furnace.

Arepresents a cylindrical boiler for steamgeneration. It is furnished with several longitudinal flues, HH, &e., that are affixed to the wall, E, is erected.

flue-sheets G G in any proper manner. The boiler A is adapted, by reason of its lines, to be set or supported in place, preferably hori- Zontal, and surrounded by a brick-masonry wall. B is the firechamber, having the usual grate-bars provided. At the rear of the fire-chamber a wall, 0, of proper height is constructed. The bridge-wall O is preferably made concentric on its top surface to the ad jacent cylindrical surface of the boilcr A, to afford a semi-annular throat through which the products of fuel combustion in the firechamber B will pass toward the rear of the boiler.

The space D below the boiler, through which the draft of the chimney draws the flame from the fire-chamber B, may be' made lower than the bridge-wall C, to allow room for the ashes that incidentally accumulate, and thus assure the free passage of heat-currents from the firechamber rearward.

At a point nearly in line with the vertical face of the rear flucsheet, G, the rear bridge- This wall is made with a curved upper surface, and is extended upwardly around the boiler to a considerable height, thus producing an annular throat or draft-port, E, that conforms to the surface of the boiler; and in regard to the space that is allowed to intervene between the surface of this curved wall E it is important to insure efficiency of operation, that the area for draft afforded by this curved port or annular pas sage E be somewhat less, superficially considered, than the area of the several fines of the boiler.

At the rear of the boiler, directly opposite the flue-sheet G and at such a distance from it as to provide a proper flue or passage for heat-currents that pass through the curved port E, a vertical wall, I, is erected parallel to the surface of the flue-sheet Gr.

The masonry walls of the furnace are made to envelop the boiler and thus retain the heat, and a proper provision is made at the front end of the boiler to accommodate a vertical chimney, into which the products of combustion pass when drawn through the fines H H.

In operation, the flame from the fire-chamber B passes over the bridge-wall 0, through the space I), over the rear bridgewall, E,

. the result of which is, that more rapid evap oration of water and evolution of steam is effected and a consequent economyin average consumption of fuel is obtained.

Having fully described my invention. wliatI claim as new, and desire to secure by Letters Patent, is

1. In a furnace for a horizonal retnrnflue boiler, the combination, with a boiler having longitudinal fines: and located in furnacewalls to receive heat from a lire-chamber below it, of a front bridge-wall, a rear bridgewall, the rear wall by its relative position in regard to the surface of the boiler affording a curved draft-port of less area than thejoined area of the flues, and an ash or cinder space or chamber located between the bridge-walls, the bottom orfloor of said space or chamber being below the upper surfaces of the bridgewalls, substantially as set forth. I

2. In a furnace for a horizontal return-flu boiler, the combination, with a boiler having longitudinal fines secured to flue-sheets, the boiler located in an enveloping wall to receive heat from a fire-chamberloeated below the boiler, and provided with a bridge-wall at its rear end,ofa bridge-wall placed near the rear end of the boiler, and constructed to produce a curved throat or draft-port, the area of which is less than the area of the lines taken together, a vertical wall to deflectheat against the rear fluesheet of the boiler, and an ash or cinder space or chamber located between the bridge-walls, the bottom orfloor of said space or chamber being below the upper surfaces of the bridgewalls, substantially as set forth.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

ROBERT STE\VART.

Witnesses:

CARL JOHNSTON, FRED. R. STARKEMIER. 

